What are the effects of water reducing agents on the shrinkage and cracking of commercial concrete?

 Overview of superplasticizer

The superplasticizer can significantly improve the fluidity of the mixing slurry so that the foam mud can reach self-leveling in the mold and reduce or even no bread. It can greatly reduce water consumption while maintaining the slump of concrete. Water reducer is also known as dispersant or plasticizer, and it is the most commonly used admixture.

The principle of water reducing agent, the specific surface area of cement is generally 350-400m2/kg, and more than 90% of cement particles have a particle size in the range of 7-80 microns, which belongs to the category of fine powder particles. For cement-water systems, the surfaces of cement particles and hydrated cement particles have a slightly polar surface and are highly hydrophilic. Fine cement particles have considerable specific surface energy (solid-liquid interface energy). In order to reduce the total heat on the surface solid and liquid, fine cement particles tend to spontaneously condense into flocs to minimize the interface energy of the system and make the system thermodynamic. keep it steady. At the same time, in the early stage of cement hydration, the surface of C3A particles is positively charged, while the surfaces of C3S and C2S particles are negatively charged.

There are three watering methods in concrete: free water combined with water and adsorbed water. In the initial stage of cement mixing, there is less chemically bound water and adsorbed water, and the mixed water mainly exists in the form of free water. However, due to the flocculation structure of the cement particles, 10%-30% of the open water is wrapped in them, thereby severely reducing the fluidity of the concrete mixture. The main function is to destroy the flocculation structure of cement particles, keep them in a dispersed state, and release free water in the packaging and flocs, thereby improving the fluidity of fresh concrete.

With the continuous advancement of society and production technology, in the construction industry, the quality and performance requirements of concrete are more stringent, and the quality of buildings is directly affected by the performance of concrete.

The invention of concrete admixture greatly improved this problem. The commercial concrete added with water reducing agent greatly improves the work performance, the strength of the concrete, and the durability and service life of the concrete. This is a remarkable achievement for the construction industry.

Water reducing agents are widely used in various key infrastructures, especially high-rise buildings, super high-rise buildings, high-speed railways, expressways, subway stations, nuclear power plants, etc., which promote the rapid development of buildings and provide a strong guarantee for the industry.

The water-reducing agent is an additive, which can significantly reduce or greatly reduce the mixing water of concrete in the concrete mixing process, improve the fluidity and the strength of concrete. The practice has been proved that if the water-reducing agent is added to the concrete if it is not necessary to increase Strength can greatly reduce the amount of cement and improve the compactness of concrete. Therefore, water reducing agent is an indispensable additional material in commercial concrete.

In order to further improve the economic benefits of commercial concrete, concrete manufacturers like to use water-reducing agents with higher water-reducing properties to increase the strength of concrete or greatly reduce the amount of cement and reduce production costs.

In fact, this is a major misunderstanding. Although water reduction is beneficial to improve the compressive strength of concrete, excessive water reduction will also have an adverse effect on the flexural strength of concrete.

Although proper water reduction is beneficial to reduce the shrinkage of concrete, it must be noted that when designing the concrete mix, the water reducing the effect of the water-reducing agent has been considered. Generally, the designed water glue is relatively low, such as further reduction. The amount of water added will increase the shrinkage of the concrete and increase the shrinkage of concrete.

When commercial concrete greatly reduces the amount of cement, although the compressive strength does not decrease, the tensile strength decreases as the volume of hardened cement stone in the concrete decreases.

Due to the reduction in the amount of cement, the concrete grouting layer is too thin, which will cause more micro-cracks in the concrete. Of course, micro-cracks have little effect on the compressive strength of concrete, but the impact on concrete tensile properties should not be underestimated. underestimated. The massive reduction of cementitious material also affects the elastic modulus and creep of concrete, making it easier to crack. When producing commercial concrete, the water reduction rate of concrete and the number of cementitious materials must be considered comprehensively. Do not reduce the water or excessively reduce the cementing material.

Application of superplasticizer

With the continuous improvement of society and production technology, in the construction industry, the quality and performance requirements of concrete are becoming more and more stringent, and the quality of buildings is directly affected by the performance of concrete.

The invention of concrete admixture greatly improved this problem. Commercial concrete mixed with a water-reducing agent greatly improves the work performance, increases the strength of the concrete, and improves the durability and service life of the concrete. This is a remarkable achievement. Mainly used in the construction industry.

Water reducing agents are widely used in various key infrastructures, especially high-rise buildings, super high-rise buildings, high-speed railways, highways, subway stations, nuclear power plants, etc., which promote the rapid development of the construction industry and strong protection industry.

The water-reducing agent is an additive, which can significantly reduce or greatly reduce the mixing water of concrete in the concrete mixing process, and improve the fluidity and strength. It has been proved that if the water-reducing agent is added to the concrete if it is not necessary to increase the strength, it can greatly reduce the amount of cement and improve the compactness of concrete. Therefore, the water reducing agent is an indispensable additive in commercial concrete.

In order to further improve the economic benefits of commercial concrete, concrete manufacturers like to use water-reducing agents with higher water-reducing properties to increase the strength of concrete or greatly reduce the amount of cement and reduce production costs.

In fact, this is a major misunderstanding. Although water reduction is beneficial to improve the compressive strength of concrete, excessive water reduction can also adversely affect the flexural strength of concrete.

Although proper water reduction is conducive to reducing the shrinkage of concrete, it must be noted that when designing the concrete mix, the water-reducing function of the water-reducing agent has been considered, and the water-cement ratio in the overall design is low, such as further reducing. The amount of water used will increase the shrinkage rate of the concrete and increase the shrinkage rate of the concrete.

When commercial concrete greatly reduces the amount of cement, although the compressive strength does not decrease, as the volume of hardened cement stone in the concrete decreases, the tensile strength will decrease.

Due to the reduction of cement consumption, the concrete grouting layer is too thin, which will cause more micro-cracks in the concrete. Of course, the micro-cracks have little effect on the compressive strength of concrete, but they cannot affect the tensile strength and other properties of concrete. The large reduction in neglected cementitious materials will also affect the elastic modulus and creep of concrete, making it easier to crack. In the production of commercial concrete, the water reduction rate of concrete and the number of cementitious materials must be considered comprehensively. Do not reduce the moisture or excessively reduce the cementitious material.

The price of superplasticizer

The price of superplasticizers varies randomly with production costs, transportation costs, international conditions, exchange rates, and market supply and demand of superplasticizers. Tanki New Materials Co. Ltd aims to help all industries and chemical wholesalers find high-quality products by providing a full range of products. If you are looking for a superplasticizer, please contact us for the latest price.

Supplier of superplasticizer

As a global supplier of superplasticizers, Tanki New Materials Co., Ltd. Has extensive experience in the performance, application, and cost-effective manufacturing of advanced and engineering materials. The company has successfully developed a series of foam concrete additives (including lightweight concrete, CLC blocks provide concrete foaming agents, superplasticizers, foam concrete strength enhancers, etc.), high-purity targets, and functional materials. Ceramics and structural equipment, and provide OEM services.